Guns for Federal Agents, Volume I: The FBI

Federal agents, both PC and NPC are part and parcel of the Delta Green campaign, and the most notable federal agency is the FBI.
This is a simplified list, intended to give a character flavor by identifying the most likely weapon issued to him or her, upon graduation from Quantico.

FIELD AGENTS
1974 to 1980 - Field agents are issued the S&W Model 10 with a 2.5″ barrel, chambered in .38 Special.
1981 to 1990 - Standard issue is the S&W Model 13 with a 3″ barrel, chambered in .357 Magnum.
1991 to 1992 - The S&W 1076, a 10mm Auto autoloader, is standard issue for all agents.
1993 to 1997 - Agents are given a choice between two 9mm Para autoloaders, the SIG-Sauer P226 and SIG-Sauer P228.
1998 to present - Agents may choose between two autoloaders in .40 S&W, The Glock G22 or Glock G23.

FBI SWAT
1974 to 1980 - S&W Model 19s with a 4″ barrel, chambered in .357 Magnum, are issued to SWAT-qualified agents.
1981 to 1990 - SWAT-qualified agents issued S&W Model 459 autoloaders in 9mm Parabellum.
1988 to 1997 - SWAT-qualified agents are issued 9mm Para SIG-Sauer P226 autoloaders.
1998 to present - SWAT-qualified agents are issued the Springfield Armory Bureau Model, a .45 ACP autoloader.

HRT TEAM
1983 to 1994 - HRT team members are issued the Novak Custom Hi-Power Mk II, 9mm Para autoloader based on FN Browning Hi-Power Mk II.
1995 to 1997 - HRT agents are issued the Les Baer Custom P14.45 SRP, .45 ACP autoloader, based on the Para Ordinance P14.45.
1998 to Present - HRT membes are issued the Springfield Armory Bureau Model, a .45 ACP autoloader.

PERSONALLY OWNED FIREARMS (POW)
Prior to 2007 the FBI has a well-developed POW policy, allowing agents to purchase and carry their own firearms, providing it met certain criteria.  SIG-Sauer and S&W (and Colt until the mid/late 1980s) were approved makes.  Revolvers needed to have a 2-4″ barrel and be of steel construction.

FBI LONG ARMS
Field agents may be issued one of several long arms, kept in the vehicle, to be used in more significant incidents.  These weapons include Remington 870 shotguns, Colt AR15A2 rifles and carbines, H&K MP5SF carbines (1989-1993) or H&K MP5/10SF carbine (from 1994).
SWAT-qualified agents are permitted to use automatic weapons, including: MP5 sub-machine guns (before 1994), MP5SD sub-machine guns, H&K Mp5/10 sub-machine guns (from 1994), Colt M16A2 assault carbines and assault rifles, Colt M-4 assault carbines (from 1998), H&K G3 battle rifles, Remington M40A1 and McMillan Model 87 sniper rifles, and Remington 870 shotguns.
HRT teams utilize the same long arms as the regional SWAT teams with the addition of H&K HK33E assault rifles, H&K PSG-1 and Barrett Model 82 sniper rifles.